Dental matrix



Nov. 16, 1937. l. E. SIQVELAND ,0

DENTAL MATRIX Filed March 25, 1935 4 16," 16" 13 v d I? i 5 B 5 1 ,44

Fifi F4946 1 v 2,099,454 I DENTAL MATRIX Ivar E. Siqveland, St Paul,Minn. n lieatiii imaiciiz's, 1935, Serial No. 12,873

1 claims. (cl; 2 's) This invention relates to the method of makingeryic hend theri 1ax and..:plasticl.fillin s iorteethaan tt emeans .o.Qbtaining virtually are t was m res i n or p e o e i U s mple ma neritu carryin out a fin r hn qu ma ng c vical and other inlays orfillings.qipr w t;:haebeen; f icult to obtain. the W simnr n;..of thesavityiowins t t e fact 2 t t e-waxsim ress n. patte n, 9 161 not he di vemqre t Wi ho s i le d tort on or ju y hereto e nthel mpre onl Wa wasPlates he ee the, too hla th m-a heated sp ee-inse te i e h wax. with, hs 3114 ni hQdr-thmsri u wash sin ce; il

tl iewax had set about thesprue and then the wax ,impressio ywas removedon n of t e spr 1e, Itwill beapparent that unlessthe dentist w iextr m lca e u th s ol method, h m ehti iu e, thea rm or a e. o h a im:

pre ssionpr. pattern; in inserting the sprueiand try ngl toremove it.from the cayity. This I have entirely overcome with my methodby-providing waxed sprues of, the desired character for difierent.cavities',iand apparatus for insertingthe waxed'sprue, intolthe' cavityso as to obtain a virtually perfect wax. impression. I a feature of vmymethod resides in providing waxed sprues of different shapes'andcharacters so that they may be readily adapted to difierentcavities-"These waxedsprues are in the form V of a short wire having theimpression wax formed in-thedesired shape on one end thereof; Inoneform, the-impressionwax on the sprue may be conical'so that the apexthereof may assist in guiding the wax. into the -cavity.= In anotherform the;wax;may -be cylindrical on one. end of theli sprue-nwire ior.tof such other shapelas. may desired: These; shorth-wireysprues withthe waxed ends are; supplied to; the dentist "in-the quanti y-an s pe es-c 1 v :i ,Jl 'he inventionincludes a suitable matrix plate havingfatubular supporting; portion through which the outer end OfJthe sprue mayextend.

1 lnQcalfrying but my 'method, I provide a V suitableljiorming' toolfor, forming, the matrix. plates to the outer contour'of'the 'tooth tobe filled.

I also provide an applying tool for holding. or supporting the matrixplate with ,thespru'e pin extendinggthmugh the same and the-waxed end ofthesp rue adjacent tothe matrix plate. This applying tool holds. thematrix "plate and sprue in applying position and is provided with aspringprged socketintowhich the-end of ;the smile Pil fit J fl a p y ntool permits th waxed sprue to be pressed by the matrix plate into thecavity, thev matrix'plate fitting closely to the outercontour, of thetooth and pressing the impression wax into the cavity firmly, so as toobtaina true-impression of the cavity while 5 the impression wax issoft-enough to be pressed into the same. The springurged socket'whichengages the end of the sprue pin ejects the sprue as; the applying vtoolisdrawn away from the tooth and thesprueipin remains projecting from 10the (impression which has become set in the cavity in the tooth ,Thenwhen-the impression wax is sufficiently set with the sprue pin anchoredtherein and projecting. therefrom, the mold may tool. holds the-same, inposition until the impression wax has. thoroughly set. p

, Myvmethod providesabetter dental technique in themakingof surfacefillings on the outer faces ofteeth, such vas cervical and-other inlaysand plastic fillings. The applying tool with the matrixplate may beused} to apply the plastic fillings in a more efiicient manner than'hasbeen accomplishediheretofore.. The features-of .my method of makingcervical and other inlayand plastic fillings will be more fully apparentfrom the disclosure of the tools desirable in, carrying out the same andthe mannerin which,- the waxed sprues are handled and applied-to. obtainthe desired impression of the cayity. 1

The drawing is for the purpose of illustrating the, carrying out of mymethod and showing the apparatus, such as the tools desirable, and the40 construction ofthe waxedsprues-and matrix plate as used inone form incarrying out my method.- y t g i In the drawing, Figure 1 is a sideelevation of a setof upper and lower teeth in biting position, showingacavity which is about to be filled by mymethodw r; I v

Figure 2 is a perspective view of the matrix plate'iused in carrying outmy method.

-,Figure 3 illustrates the bending and shaping pliers used for holdingand .forming the matrix 1 plate'to the. shape of the-tooth. i;

Figure lnillustrates almatrix plate bent into the desiredshape. l a v v.Figure 5.illustrates a waxed sprue of one form.

Figure 6 illustrates a waxed sprue of another form.

Figure '7 illustrates a waxed sprue of still another form.

Figure 8 illustrates the applying tool with a waxed sprue and matrixplate held as a unit and ready for taking an impression of a cavity in atooth.

Figure 9 is a sectional detail of the operating end of the applyingtool, showing its position in taking an impression of a cavity in atooth and showing the manner in which the matrix plate. operates topress the impression wax into the.

cavity and showing the position of the sprue pin in the applying toolcushioned by the spring means in the tool.

Figure 10 is a section of a tooth, which shows the impression wax withthe sprue pin projecting therefrom after the impression of the cavityhas been taken and the applying tool with the matrix plate has beenwithdrawn from the tooth.

Figure 11 illustrates a perspective of the removed sprue pin andimpression after the wax impression of the cavity has been taken by mymethod, as illustrated in Figures 9 and 10.

Figure 12 is an enlarged section of a waxed sprue.

In carrying out my method of making cervical and fillings of a similarcharacter, I use a matrix plate III which is formed of thin sheet metalor other suitable material, such as celluloid. This matrix plate It isprovided with a tubular shank II having a hole I2 extending through thesame.

The matrix plate I is adapted to be cut with the desired peripheralshape and may be formed by supporting the same in the holding plierswith the shank II extending in the slot I3 of the bifurcated end of thepliers A as illustrated in Figure 3. One of the jaws I4 of the pliers Amay be round in cross-section so that the matrix plate I0 may be formedaround the same while it is held between the jaws of the pliers A.

To assist me in further carrying out my method I employ waxed sprues B,illustrated in Figures 5, 6 and '7. The sprues B consist of a wire shankI on one end of which a body of wax I6 is formed in any desired shape.Thus I provide a waxed sprue B with a wire shank I5 and with a body ofwax such as I6 in spherical form, I6 in conical form, or such as in theform illustrated by I6", or in any other shape that may be desired.These sprues B may be furnished to the dentist in any quantity and shapethat he desires.

The advantage to the dentist in having waxed sprues B with theimpression wax on the end of the same will be apparent in that thedentist may take a sprue of the desired shape and size for therespective cavity and secure an impression of the cavity to be filledvery readily.

Further, my method is carried out by the use of the applying tool Cwhich is formed with a handle portion II from which projects theoperating arm I8. On the working end of the operating arm I8 I provide acylinder I9 in which is located a coil spring 20 which is adapted toresiliently position the socket 2| within the cylinder I9 so as tonormally urge the socket 2I toward the tubular collar 22 which ispositioned in the outer end of the cylinder I9. The collar 22 is formedwith an axial opening 23 which is adapted to receive the shank II andthe sprue B collectively, as illustrated in Figures 8 and 9.

In carrying out my method of making cervical and other fillings in theoperation of securing the impression of the cavity in the tooth, the

matrix plate I0 is formed into the desired shape by first trimming theedge of the plate III to the shape desired and then forming the samewhile held by the pliers A. Then the desired sprue B is placed with itsshank I5 extending into the shank I I of the matrix II] and then thisunit consisting of the matrix and sprue, is placed into the sleeve-likecollar 22 of the applying tool G. Then the dentist is ready to take animpression of the cavity 24 and this is done by having the impressionwax I6 warm. enough to readily form itself to the shape of the cavityand then by taking the applying tool C and pressing the matrix plate I0against the outer surface of the tooth D forcing the impression wax intothe cavity 24 firmly, and as soon as the same has set, the applying toolis withdrawn, whereupon the impression wax I6 will remain in the cavity24 and the pin I5 of the sprue B will project from the same asillustrated in Figure 10. The dentist may then remove the sprue B withthe wax impression E of the cavity 24 formed thereon as illustrated inFigure 11. It will therefore be apparent that with my method of securingthe impression of a cavity to be filled, a dentist may accomplish thesame with a finer technique than was possible heretofore and with fullassurance of obtaining virtually a perfect wax impression of the cavityin the tooth such as D. Heretofore, the dentist could not carry out thisfine dental technique, not being advised of my method or manner ofcarrying out the same, and not having the waxed sprues, matrix plate orapplying tool it was not possible for the dentist to easily obtain avirtually perfect impression of the cavity to be filled. With my method,cervical and other fillings may be made very readily by the dentist withfull assurance of obtaining a perfect impression of the cavity, and thewax impression is easy to handle owing to the fact that the sprue wireI5 is firmly embedded in the central portiorr.

of the impression.

The wire shank I5 of the sprue B may be threaded or formed with aroughened end at I5 so as to more firmly hold the wire shank I5 embeddedin the wax I6. Therefore, my method of making cervical and otherfillings comprises preparing a matrix plate to the desired shape,connecting a waxed sprue with the matrix plate so that they may beoperated as a unit, then supporting this unit of matrix plate and spruein a manner to permit the impression wax to take a true impression of acavity to be filled. When the impression is taken, the sprue wirepermits the easy removal of the wax impression of the cavity withoutdistorting or injuring the impression and then the dentist may cast atrue inlay. Further, the method provides a means of making plasticfillings by using the matrix plate to support the plastic filling andthen with theapplying tool forcing the plastic filling into the cavity.Thus I provide a method wherein the finest dental technique may beaccomplished in, making fillings of the character set forth, with thegreatest of ease. I j

I claim:

1. A matrix for filling dental cavitiesincluding a flexible plate formedto the curvature of the tooth, and a hollow shank secured theretoproviding an opening entirely through the shank and plate. Y

,2. A matrix for supporting wax including a plate of soft materialflexible to fit the curvature of a tooth, and a shank projecting fromone surface thereto having an opening extending through said shank andplate.

3. A cavity filling means comprising a matrix plate to fit the outerconformity of a'tooth, said plate having an opening therein, and meanssupporting cavity filling material adjacent said plate including a sprueextending through said opening having cavity filling material on the endthereof.

4. A cavity filling means comprising a matrix plate to fit the outerconformity of a tooth, a shank thereupon, said shank having an openingtherethrough extending also through said plate, and means for supportingimpression material adjacent said plate including a sprue bearingimpression material extending through said opening.

IVAR E. SIQVELAND.

